A MOMENT OF CULTURE CLASH: In the U.S., new parents often hesitate to expose their newborns to crowds. But the morning after Mateo was born, more than two dozen relatives crowded the hospital room in Madrid, hugging and kissing the baby and chattering in boisterous Spanish.

She spoke her native Spanish, and she spoke ballet — tendu, arabesque, battement jeté. But she couldn't understand what the gregarious American dancer was saying when he chatted and laughed with others in the Zurich Ballet.

"I saw Matthew always talking with everyone, and I thought: I wish I could understand him," Ana remembers. He thought she was shy, or uninterested, or maybe his jokes were falling flat.

Finally, at a party, the rooms crammed with people, Ana made the first verbal gambit. "We were both giving each other these googly eyes," Matthew says. "And she said, 'Obviously, we're feeling something here.' "

He was about to leave Zurich to dance in Spain, then to manage a ballet company in Germany. They traveled back and forth to see each other on weekends. Finally, both landed in Spain to be part of the brand-new Barcelona Ballet.

"Matthew asked me to marry him many times. But I thought, 'Not yet. We have time,' " Ana says. Then, abruptly, his every-other-month proposals stopped. They were dancing in Merida, in a spectacular old Roman theater, when Matthew proffered a ring he'd fashioned from a sequin pinched off Ana's costume.

This time, she said yes. But at lunch afterward with her parents, she kept flashing Matthew "don't say anything" signals. When she did share the news with her parents, they were not overjoyed.

"They wanted a Spaniard with a nice office job, not a Texan who is a dancer and didn't go to college," Matthew says. But Ana trusted that they'd warm to the idea; sure enough, her mother called the next day with thoughts about wedding attire, music, and flowers.

Their 2010 wedding, in a small town near Madrid, was a six-hour extravaganza with a DJ and a live band, a flamenco group, Ana's large extended family, Matthew's mother and older brother, his father in a cowboy hat, his 80-something grandmother on her first trip out of the United States.

Matthew wanted kids right away. But Ana lobbied to wait: there was always another role she yearned to dance. "For a ballet dancer, pregnancy is very hard — it's a lot of months of not working 100 percent. Then, recovery. And then you have a baby. I would say, 'Next year, maybe.' But the next year there would be a ballet that was important to me."

When government funding for the arts withered in Spain, the pair decided to take a leap and try New York, trading their four-bedroom apartment in the mountains for a micro-efficiency on the Upper East Side. It took Ana six disheartening months to get her green card; meanwhile, Matthew was traveling the world to book tours for dance groups.

Once Ana could work legally, she joined the Houston Ballet; again, they lived long-distance, two-and-a-half years of criss-crossing the country until, finally, she landed with the Pennsylvania Ballet in 2015.

At least they were on the same coast. And they were over 30. They got pregnant on the first try, and Ana discovered she liked the challenge of dancing with a changing body. "Dancers use their core, but my core was not there any more. My balance was different. It was like discovering myself again with a different body."

Last November, she performed at the Merriam, dancing in a multitoned unitard in a world premiere called It goes that way, with music by Laurie Anderson. A reviewer commented, "Calderon's pregnant belly was apparent, and it was refreshing to see a pregnant dancer featured like this."

Ana was 36 weeks pregnant — she and Matthew had just moved into a house in Fairmount — when she got a phone call from her brother: their father had suffered a severe heart attack. They flew to Spain immediately. Ana's father died the next day.

Although they'd planned to deliver at Pennsylvania Hospital, it suddenly made sense to stay. Spain boasts national health care, and Ana's whole family was there for support. They were all still in shock from her father's passing, and Ana didn't want her mother to be alone in the house.

Mateo made them wait. He arrived a week overdue, after four days of irregular contractions, an induction, and a 12-hour labor that left Ana — despite the stamina she'd gained from dancing — so exhausted she could barely lift her arms to hold the infant.

Matthew was startled, then pleased, that the baby looked like him. "That first night in the hospital, I had a little bit of a panic. It was just the two of us and this baby: Oh, now what? What have we gotten ourselves into?" It helped that Mateo was a calm infant who slept well, nursed hungrily, and weathered plane trips — to London at one month, to Texas at two months, and finally home to Philadelphia at four months — with tranquillity.

Jose Luis Pita da Veiga

Ana, Matthew, and Mateo relaxing in Spain in August 2018.

Ana is back in the studio; she performed for the first time post-partum in last month's Romeo and Juliet. Matthew's work as an artist manager takes him all over the world: Peru, San Francisco, Russia. An au pair helps, and when Matthew is in Philadelphia, he can be with Mateo on the nights when Ana performs.

It's not easy, they say. But neither is ballet, or living apart — sometimes multiple time zones apart — for most of their relationship. "I never considered not to keep dancing [after pregnancy]," Ana says. "I never thought it would be bad for the baby. I think it was the opposite: I was so healthy, and with so much energy, and I think the music was good for him."

Ana avoids taking Mateo to the studio or the theater — an infant is a distraction, and they're there to work. On the few occasions when she has, the other dancers got excited: It's rare to have an infant in their midst. But Mateo just takes in the lights, the colors, the music he's heard since being in utero. He's peaceful, and at home.